Document how to use `mpremote` for a faster feedback loop

[jecaro]

I got very frustrated working on my badger. My feedback loop was:

• edit files
• double click reset for disk mode
• rsync the files
• click reset
• see errors or that it does not satisfy me
• repeat

And it was so cumbersome that I gave up a few times.

Looking for code examples on GH, I discovered that one can use mpremote to execute python code on the badger while plugged in (was in some Claude skill file). And it was way better:

• edit files
• run mpremote
• repeat

This information should definitely be present in the documentation.